code: def mu_law_encoding(signal, quantization_channels):
      """Encode signal based on mu-law companding. Also called mu-law compressing.
  
      This algorithm assumes the signal has been scaled to between -1 and 1 and returns a signal encoded
      with values from 0 to quantization_channels - 1.
      See `Wikipedia <https://en.wikipedia.org/wiki/Μ-law_algorithm>`_ for more details.
  
      Args:
          signal (float `Tensor`): audio signal to encode
          quantization_channels (positive int): Number of channels. For 8-bit encoding, use 256.
  
      Returns:
          signal_mu (int `Tensor`): mu-encoded signal
      """
      mu = quantization_channels - 1.0
      signal_mu = (
          tf.math.sign(signal)
          * tf.math.log1p(mu * tf.math.abs(signal))
          / tf.math.log1p(mu)
      )
      signal_mu = tf.cast(((signal_mu + 1) / 2.0 * mu + 0.5), tf.int32)
      return signal_mu
  
file_path: kapre/kapre/backend.py
imports: from tensorflow.keras import backend
  import tensorflow
  import numpy
  import librosa
label_desc: Use image node_id 6 for calling a global function with example usage: mu_law_encoding(signal, quantization_channels) and returns: signal_mu